The present invention relates to apparatus for transporting photographic films, and more particularly to improvements in apparatus for stepwise transport of elongated webs of photosensitive material. Still more particularly, the invention relates to improvements in apparatus which can be utilized for stepwise transport of exposed and developed photographic films through a copying machine so as to place selected frames of the film into register with the copying station.
It is known to provide selected film frames of an exposed and developed photographic film with indicia which can be detected by automatic monitoring devices for the purpose of generating signals which are used to arrest the film whenever a selected film frame registers with the copying station. Such mode of operation is desirable in order to guarantee that the film is arrested only when a frame whose image is to be reproduced is in register with the copying station, i.e., the transport of film between successive stoppages should take place at a maximum speed to ensure that the copying machine can turn out a large number of prints per unit of time. Heretofore known transporting apparatus are not entirely satisfactory, either owing to excessive complexity, due to relatively low speed of transport of the film between successive stoppages, or owing to failure of conventional apparatus to arrest the film in exact positions of register of selected frames with the copying station.